I e-mailed the contact at getchill.net, asking him for references for the models if you ran the app on his site. His response below, good reading, particularly if you are not ready yet to settle for "42." :-)
***** Hi Jon, Here are some of the references I used to compute the chill accumulation for each model. Hope this is what you are looking for. I personally only use the below 45 model. There isn't a lot of information about ratings for fruit trees using the dynamic model. Utah models give wacky results in my warm winter climate (San Diego). A reference for Utah, Positive Utah, and Dynamic models. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3077742/ A guide to calculate chill portions using the dynamic model. http://ucanr.edu/sites/fruittree/How-to_Guides/Dynamic_Model_-_Chill_Accumulation/ Some fruit trees rated in chill portions using the dynamic model. http://fruitsandnuts.ucdavis.edu/Weather_Services/chilling_accumulation_models/CropChillReq/ Here is the correct link for Utah, Positive Utah, and Dynamic models. I accidentally pasted the wrong one above. http://agis.ucdavis.edu/publications/2009/Sensitivity%20of%20winter%20chill%20models%20for%20fruit%20and%20nut%20trees%20to%20climatic%20changes%20expected%20in%20California's%20Central%20Valley.pdf Thanks, Tom On Wed, Dec 23, 2015 at 6:17 PM, Kevin Hauser <ke...@kuffelcreek.com> wrote: > Jon, that was an articulate and correct explanation of the current thought > on chilling units. However, I should point out that it's full of holes > when it comes to apples, such as how "low chill" Anna and Dorset Golden > (Bahamas) grow just fine in zone 4 upstate New York, where they blossom in > April along with the other apples instead of in January like they do here. > Or why on our 100 chilling hours we're still able to grow "high chill" > super-hardy apples like Wealthy and Black Oxford, which incidentally > blossom about the same time they do up north, even though it may have been > 100 degrees here for weeks. I'd say day length may have something to do > with it, but even that doesn't answer all the questions. > > I just assure clients that "the tree knows what to do" and to plant > whatever apple variety they want, and to ignore the chilling hours. Wish I > could say the same for peaches (the disease-ridden bug-infested > squishy-fruited chilling hour monkeys). > > Merry Christmas all > > Kevin Hauser > Kuffel Creek Apple Nursery > Riverside, CA > Nakifuma, Uganda > > On Wed, 23 Dec 2015 14:57:53 -0500, Jon Clements <jon.cleme...@umass.edu> > wrote: > > It's not getting any better: > > > > http://jmcextman.blogspot.com/2015/12/dont-panic.html > > > > Comments/corrections from those more knowledgeable than myself on this > > subject are welcome. (No climate change deniers allowed though!) > > > > Have a Happy Holiday. > > > > Jon > > > > On Fri, Dec 11, 2015 at 8:17 AM, Arthur Kelly <kellyorcha...@gmail.com> > > wrote: > > > >> Should I be worried about this weather? Not that there's anything I > can > >> do about it. Mid-December and in the 50's in Maine! > >> > >> -- > >> Art Kelly > >> Kelly Orchards > >> Acton, ME > >> > >> _______________________________________________ > >> apple-crop mailing list > >> apple-crop@virtualorchard.net > >> http://virtualorchard.net/mailman/listinfo/apple-crop > >> > >> > > -- > Kevin Hauser > -- Jon Clements aka 'Mr Honeycrisp' UMass Cold Spring Orchard 393 Sabin St. Belchertown, MA 01007 413-478-7219 umassfruit.com
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